This invention relates in general to the construction of weapons and in particular to a new and useful gastight seal of a gun barrel having an insert for firing a cartridge of a small caliber.
German utility model No. 80 09 469 (U.S. Pat. No. 4,404,765) discloses an arrangement for firing cartridges from a barrel having a larger caliber than the ammunition. Provided is a barrel insert which can be introduced into the barrel axially and locked radially, and has a tapering bottom portion which is to apply against a conformable opposite surface of the cartridge chamber. The cartridge chamber is axially fixed relative to the barrel insert by the breech block.
To operate a gun with a barrel insert safely, a gastight seal must be provided between the cartridge chamber and the bottom of the barrel insert.